Response Surface Methodology Optimization of Dried Apple-Blackcurrant Cubes

Abstract

A study was conducted to investigate the effects of apple juice concentrate and blackcurrant concentrate (BCC) syrup mixture level, osmotic soaking time and drying temperature on the drying characteristics and ascorbic acid content of the dried product using the response surface methodology, as well as to determine the optimized conditions for hot air drying of the blackcurrant-infused apple cubes. The drying of blackcurrant-infused apple cubes consist of only one falling rate period (FRP) with no constant rate period. The critical moisture content of infused apple cubes increased with decreasing soaking time, the FRP drying coefficient increased with temperature, the equilibrium moisture content decreased with increasing temperature and decreasing soaking time and the ascorbic acid content increased with BCC level and soaking time. The optimized conditions for hot air drying of the blackcurrant-infused apple cubes were derived. Practical Applications The response surface methodology was used to derive mathematical models for describing the effects of the independent variables on the dependent variables for dried blackcurrant-infused apple cubes. Infusion of apple cubes using apple juice concentrate and blackcurrant concentrate would enable the production of dried products with natural sugar and high in ascorbic acid. The information obtained in this work will be valuable in producing dried blackcurrant-infused apple cubes at optimum pretreatment and drying conditions.